I have read an article in Network World about the real investment protection of the Catalyst 6500. I think the article is lousy and biased, focusing on an analyses of speeds and feeds and thinking that the only reason for network upgrades is raw throughput. Moreover, there were some comments to that article which pointed in the same direction. Everything is subject of opinion, here's my own:
Anyone that has ran a network knows it's not just about how many ports a switch has and how many packets per second it moves. This post is so simplistic at that ... and some comments below as well ...
Yes an Arista 7050 can do 64 linerate 10GE ports in one RU. It better ... it's been designed in 2011, I'd expect it to do that. But, can it do that for running inter-vlan routing for 1000+ different vlans concurrently, hundreds of HSRP groups? having ACLs applied to the SVIs with tens of thousands of lines each, running BFD on uplinks providing sub-second convergence, routing for 10K mcast groups or more, etc.? ... Can it be used to extend LANs over an MPLS backbone? ... Can it ...? The list would be TOO long. Way too long. And it would apply to switches from other vendors too.
Mid-size to large companies and many small ones NEED those capabilities. Running a network means running hundreds of vlans with policy applied to them, etc. If a company doesn't need any such thing, or just need a dozen vlans with static routing, sure they can use a lower end switch. And they do. And that's fine. And that's why Cisco also has other products in the portfolio.
Reality is, if a customer did an investment five or six years ago in a Catalyst 6500, he may have also considered at the time a Nortel 8600 (now virtually dead), or a F10 E600 (no comments), or a Foundry Big Iron 8000 or and RX-16. Had they gone with one of those, look at how much hardware (or even software) upgrade options are left for them ...
But no. Most of them went with a Catalyst 6500, and as much as it hurts other vendors (and some people on the grey market for some reason that escapes my understanding), those customers know that did the right choice. And today, those customers have options for upgrading and increasing the value of their investment and solving new network problems. Those upgrade options may be great for some, and maybe insufficient for others (which is why Cisco also has other products in the portfolio).
And Art, another angle you are totally missing is operational aspects. Running a Cat6500 with a Sup2-T presents no operational change at all for customers, no re-learning, no re-scripting, etc. THAT is also investment protection. THAT would be impossible had they invested on another vendor when they chose to trust Cisco.
Finally, I'd like to add that Sup2-T enhances the performance of a Catalyst 6500 is ways beyond pps. Any Catalyst 6500 running with combinations of 67xx cards, 61xx and others just by replacing the Sup with new Sup2-Ts get to use up to 4x more vlans, 4x more entries on the netflow tcam, flexible network, vpls available to every port, SGT/CTS and many more features.
So yes, there is investment protection. And even more when you compare with other products that have been in the market for a while, no matter which vendor you pick.